Michigan Moose Population Negatively Affected by Back-to-Back Severe Winters

This week, the Michigan Department of Natural Resources reported the results of its 2015 moose population survey in the western moose range of the Upper Peninsula.

The report shows a significant decrease in the region's moose population. Back-to-back hard winters are considered to be among the factors.

The 2015 population estimate in the western U.P. is 323, compared to an estimate of 451 in 2013. From 1997 to 2007, surveys in Baraga, Iron and Marquette counties suggested the U.P.’s moose population was growing at about 10 percent per year. From 2009 to 2013, surveys showed the growth rate slowing to about 2 percent per year.

“There is inherent uncertainty with any population survey, and due to the fact that the 2013 and 2015 estimates have some overlap in confidence intervals, the potential remains that the state’s moose population has remained steady rather than declining,” said Chad Stewart, deer, elk and moose management specialist for the DNR. “However, coupled with survey records that show a decrease in the number of moose calves seen with cows this year, it’s quite possible that we’re looking at a considerable drop in numbers.”

Researchers have suggested the following reasons for the decline in numbers:

• Back-to-back severe winter weather that negatively affected moose condition, survival and reproductive success.
• Year-round climatic changes, especially warmer temperatures, that led to increased parasite loads on moose, weakening their overall condition.
• A possible increase in wolf predation on moose calves due to the region’s lowered deer population.

The area of moose in the western Upper Peninsula covers about 1,400 square miles. Every other year, the DNR surveys most of that area from the air.

In 2015, the flights covered 80 to 90 percent of where the western U.P. moose population is located.

The next moose population survey is planned for early 2017.

The DNR will again recommend to the Michigan Natural Resources Commission that there be no moose hunt in the state.